13
Board functions
This chapter explains all the functions, peripherals, and interfaces of the board (Refer to
,
Section 8 Hardware layout and configuration
Figure 4. B-G474E-DPOW1 top layout view
, and
G474E-DPOW1 bottom layout view
).
13.1
USB Type-C
®
The B-G474E-DPOW1 product supports a USB FS 2.0 interface on a CN2 USB Type-C
®
receptacle connector.
The B-G474E-DPOW1 product offers compatibility with USB Type-C
®
Rev 1.3, USB PD3.0, and with USB battery
charging 1.2.
Caution:
The B-G474E-DPOW1 Discovery kit does not support the connection of low-power USB Hosts on USB Type-C
®
CN2 connector. As required by the USB Type-C
®
specification, the B-G474E-DPOW1 product can interface on
CN2 with USB2.0 and USB3.x Legacy High power Hosts supporting USB Full speed data link, but some feature
restrictions apply:
•
JP5 must not be set on USBC.
•
SB31 must be removed.
This ensures the USB Type-C
®
CN2 connector can only power the digital power buck-boost feature of the
Discovery board.
Caution:
The total drawn current on USB Type-C
®
V
BUS
must not exceed 3 A in any application.
CubeMonitor-UCPD tool, available on
, can be used to modify the desired allowed voltages, but the
user must not use the CubeMonitor-UCPD tool to add 5 A PDOs.
Note that the B-G474E-DPOW1 Discovery kit offers also the possibility to connect any external Display
compatible with 3 V I
²
C interface: PB8/PB9 PIOs are free to use on the CN9 extension connector and they offer
access to I2C1_SCL and I2C1_SDA alternate functions.
The USB Type-C
®
CN2 connector can be used to demonstrate different features of the B-G474E-DPOW1.
1.
Power the Discovery board with a 5 V regulated power supply source, thanks to LTC3114-1 5 V converter.
2.
Power the digital power buck-boost VIN input voltage.
3.
Power the audio Class-D amplifier feature.
13.1.1
Power the 5V general supply
The USB Type-C
®
CN2 connector can power the Discovery board with a 5 V regulated power supply
source thanks to the LTC3114-1 5 V converter U6 (Refer to
):
A jumper must be set on JP5 to select a USBC configuration. In this mode, USBPD_VBUS nominal voltage must
not exceed the 5V to 15 V range. Even if the LTC3114-1 5V converter can withstand a USBPD_VBUS nominal
voltage of 20 V, the digital power buck-boost feature supports only a USBPD_VBUS nominal voltage of 15V
maximum.
In this mode, note the USB Low power Hosts and USB 2.0 or USB 3.x Hosts are not supported.
Thanks to the UCPD controller of the STM32G474RET6, and as the UCPD_CC1 and UCPD_CC2 inputs are
respectively connected to the UCPD_DBCC1 and UCPD_DBCC2 inputs, the USB Type-C
®
allows direct power-
up of the Discovery board with a 5 V V
BUS
nominal voltage. The current protection is managed thanks to two I/Os
controlled by the STM32G474RET6 microcontroller: they are driving the LTC3114-1 5 V converter maximum
allowable output current, up to 950 mA typical.
These two I/Os are named USBPD_550mA_PROTECT (PD2) and 5V_USBPD_1A_PROTECT (PC12) in
schematics. By default, the two I/Os are deactivated, and the current protection on the 5V general supply is fixed
at 380 mA typical, thanks to R101.
UM2577
Board functions
UM2577
-
Rev 2
page 25/54
